Jeep J-10 Series 1982 Technical & Service Manual page 278

1G-16 IGNITION SYSTEMS
Service Diagnosis (Continued)
Condition Possible Cause
Correction
ENGINE DOES NOT
OPERATE SMOOTHLY
(1)
Spark plugs fouled or faulty.
(1)
Clean and gap plugs. Replace as
required.
AND/OR
ENGINE MISFIRES
AT HIGH SPEED
(2)
(3)
Ignition wires faulty (including
electronic retard).
Spark advance system(s) faulty.
(2)
(3)
Check wires. Replace as required.
Check operation. Repair as
required.
(4) S-terminal shorted to starter S-
terminal in solenoid.
(4)
Replace solenoid.
(5)
Trigger wheel pin missing. (5)
Install pin.
EXCESSIVE FUEL
CONSUMPTION
(6)
(7)
(1)
(2)
(3)
Ignition wires not connected in
correct firing order.
Two plug wires of consecutive
firing cylinders routed next to
each other.
Incorrect ignition timing.
Spark advance system(s) faulty.
MCU (microprocessor) faulty.
(6)
(7)
(1)
(2)
(3)
Connect wires correctly.
Re-route plug wires away from each
other.
Check timing. Adjust as required.
Check operation. Repair as required.
Test system. Repair as required.
ERRATIC TIMING
ADVANCE
(1)
(2)
Faulty vacuum advance
mechanism.
Centrifugal advance weights
sticking.
(1)
(2)
Check operation. Replace if
required.
Remove dirt, corrosion.
TIMING NOT
AFFECTED BY
VACUUM
(1)
(2)
Defective vacuum advance
mechanism.
Vacuum advance mechanism
adjusting screw too far
counterclockwise.
(1)
(2)
Replace vacuum advance
mechanism.
Turn screw clockwise to bring
advance within specifications
(Chapter 1A).
(3) Pickup coil pivot corroded.
(3)
Clean pivot.
INTERMITTENT
OPERATION
(1)
Loose or corroded terminals.
(1)
Tighten terminals, remove
corrosion, apply electrical
grease.
(2)
Defective pickup coil.
(2)
Perform pickup coil test.
(3)
Defective control unit. (3) Perform control unit tests.
(4)
Loose ground connector
in distributor.
(4)
Clean and tighten ground
connection.
(5) Wires to distributor
shorted together or to
ground.
(5)
Check for frayed,
pinched, or burned
wires.
(6)
Trigger wheel pin missing.
(6)
Install new pin. 70866B